Screw gearing



"April 2s, 1925.

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Inventor.: M 1 M.

Patented Apr. 28, 1925..

UNITE ST 'IES S CR-EIV GEARIN G.

Application filed September 5, 1924.

T all who/m it may] concern.'

Be it known that I, FRIEDRICH G. B. RDEL, a citizen of the German Republic, residing at Oetzscherweg 6, Leipzig, Germany,

have invented nev7 and useful Improvements Relating to Screw Gearing, of which the following is a full, clear, concise, and exact description, reference being had to the accompanying drawing, forming a part of this specification.

My invention relates to screw gearing and it has particular relation to the provision of improved means for utilizing ball bearings in the lead spindles of lathes and in analogous situations.

My experience is that ball bearings have not been heretofore employed in the locks for the nuts of lead spindles and this despite the fact that in such spindles and nuts there is a very rapid wear in the threads whereby the work performed on such machines, especially when cutting screw threads, gradually becomes more and more inaccurate. It would seem desirable to reduce the wear in the spindle and nut by introducing ball bearings between the threads of said spindle and nut. 'Ihis latter, however, has not been accomplished so far as I am aware, since upondisconnecting the locl; of the lead spindle nut and further upon the moving apart of the upper and lower halves of said nut, the balls mounted in the upper half fall out.

In the construction which I hereafter describe, the problem has been solved in that it is possible, in such construction, to utilize hardened spindles, hardened nutthreads, and hardened balls as will hereafter be described. These balls are retained in the threads of the upper and lower halves of the nut by means of a novel retaining band which is so fitted in the halves of the nut that the balls are prevented from falling out. It has, of course, been necessary to evolve an entirely new ball-retaining means, since the ball cages having cylindrical surfaces are not capable of properly retaining` the bearing balls in position in screw-threaded and divided nuts of screw gears.

In connection with my invention, Fig. 1 thereof is a vertical view, partially in section, through the lock of a lead spindle nut, the well-known lock portions for moving the Serial No, 738,l26.

two halves of the nuts towards one another being omitted; and

F ig. .2 is a plan view of the lower half of the lock nut.

In the drawings, a lead spindle 1 is provided with threads 2. A lock nut comprises a lower half y3 and an upper half 11,the said halves of the nut being composed of hardened steel and being secured in a lock 12. Hardened wedges 5 are axially inserted between bearing balls 7, which latter are a1'- ranged to furnish the bearing surfaces between the screw gearing spindle inthe aforesaid bearing comprising the halves 3 and 11.

As hereafter pointed out, it is essential that the balls be retained in position so that they will not fall out upon the separation and moving apart of the two halves of the lock nut. I accomplish this by providing ballretaining bands 13 of a novel form, which, it will be observed, are fitted into the path of the balls 7 in a helical manner whereby the said balls are prevented from falling out. The aforesaid bands 18 are preferably com.- posed of steel and are secured at their ends, by means of longitudinally extending members 14, to the surface 15 of the lock nut, the screws 16 being employed to secure the band as shown.

As will be noted from the drawings, these bands are of such character that they pass over the balls and down between the saine into contact with the wedges 5. In other words, the bands 13 pass over t-he surface of the balls while between each two balls they (the bands) engage with the flat surface of the wedges 5.

From the foregoing description, it will be apparent that I have provided means which may be utilized in connection with a lead spindle for screw gearing or in other analogous situations whereby ball bearings can be advantageously employed and yetI wherein said ball bearings are properly retained in position upon the separat-ion of the lock nut surrounding the spindle and providing the bearing therefor.

`While I have shown but one embodiment of my invention, it is apparent that many modifications therein may occur to those skilled in the art, and I desire, therefore, that my invention be limited only by the prior art and the soope of the appended claims.

Having thus described niy invention, what I claim as new and desire to secure by Letters Patent oiI the U. S. is

l. In a ball beiring- 'for lend spindles und the like a threaded spindle, e bearing ineinber snrrounding` the saine`Y bell bearings nssoeiated with the threads ot said spindle, retaining members disposed axially oi seid spindle and retainingl seid balls, sind seein'- ing Ineens extending interiorly et seid bearingl memberl :1nd over said balls.

2. In e bull bearing ifor lead spindles end the like, a threaded spindle ineinbei',hea1 ing balls associated with said threads, a lock member surrounding said spindle, axially disposed ineens for retaining said bulls and ball-retnining bands extending' over seid balls and secured to said bearing.

3. In a bell bearingl for spindles and the like, zi. threaded spindle, e divided lock nut therefor, bearing bells associated with the threads oi seid spindle, and bearing bands ,ies

extendingparallel to the threads of the spindle sind over the surface oit the balls, said bands being indented between eaeh two balls whereby the latter :rre secured firmly in place.

4. In a. ball bearing for lead spindles and the like, e threaded lend spindle, n divided lock nut snrrminding the saine,y bearing bells associated with the threads of seid spindle, axially extending wedges serving to secure seid bells, and bearing bands secured :it their outer ends to the upper and lower halves ot' seid look nuts, said bends beingr arranged parallel to the threads olf seid nnt and along` the surface ot' the balls sented in the threads of the spindle, and between meh two bells being` substantially in Contact with the liet surfaces of said wedges.

In Witness whereof,l I have hereunto snhscribed my naine.

FEIEDRCH GUSTAVBERNHRD RDEL.

Witnesses -RUDOLPH Fermin, l,VILLY S'rinn. 

